Steerable miniature jumping robot

Jumping is used in nature by many small animals to locomote in cluttered environments or in rough terrain. It offers small systems the benefit of overcoming relatively large obstacles at a low energetic cost. In order to be able to perform repetitive jumps in a given direction, it is important to be able to upright after landing, steer and jump again. In this article, we review and evaluate the uprighting and steering principles of existing jumping robots and present a novel spherical robot with a mass of 14g and a size of 18cm that can jump up to 62cm at a take-off angle of 75°, recover passively after landing, orient itself, and jump again. We describe its design details and fabrication methods, characterize its jumping performance, and demonstrate the remote controlled prototype repetitively moving over an obstacle course where it has to climb stairs and go through a window. (See videos 1-4 in the electronic supplementary material.

Vestibular Effects on Cerebral Blood Flow

Background: Humans demonstrate a number of unique adaptations that allow for the maintenance of blood pressure and brain blood flow when upright. While several physiological systems, including cerebral autoregulation, are involved in this adaptation the unique role the vestibular system plays in helping to maintain brain blood flow is just beginning to be elucidated. In this study, we tested the hypothesis that stimulation of the vestibular system, specifically the otoliths organs, would result in changes in cerebral blood flow. Results: To test our hypothesis, we stimulated the vestibular organs of 25 healthy subjects by pitch tilt (stimulates both canals and otoliths) and by translation on a centrifuge (stimulates otoliths and not the canals) at five frequencies: 0.5, 0.25, 0.125 and 0.0625 Hz for 80 sec and 0.03125 Hz for 160 sec. Changes in cerebral flow velocity (by transcranial Doppler) and blood pressure (by Finapres) were similar during both stimuli and dependent on frequency of stimulation (P < 0.01). However, changes in cerebral blood flow were in opposition to changes in blood pressure and not fully dependent on changes in end tidal CO2. Conclusion: The experimental results support our hypothesis and provide evidence that activation of the vestibular apparatus, specifically the otolith organs, directly affects cerebral blood flow regulation, independent of blood pressure and end tidal CO2 changes

Transparent Object Proxies for JavaScript (Artifact)

This artifact provides two prototype extensions of the SpiderMonkey JavaScript engine. Both extensions implement alternative designs for transparent proxies that are better suited for use cases such as certain contract wrappers and access restricting membranes. The first prototype extends the proxy handler by an isTransparent trap that regulates the proxy\u27s transparency. The second prototype implements a new global object TransparentProxy that implements the constructor for transparent proxy objects

The Quasar Outflow Contribution to AGN Feedback: VLT Measurements of SDSS J0318-0600

We present high spectral resolution VLT observations of the BAL quasar SDSS J0318-0600. This high quality data set allows us to extract accurate ionic column densities and determine an electron number density of n_e=10^3.3 +/- 0.2 cm^-3 for the main outflow absorption component. The heavily reddened spectrum of SDSS J0318-0600 requires purely silicate dust with a reddening curve characteristic of predominately large grains, from which we estimate the bolometric luminosity. We carry out photoionization modeling to determine the total column density, ionization parameter and distance of the gas and find that the photionization models suggest abundances greater than solar. Due to the uncertainty in the location of the dust extinction, we arrive at two viable distances for the main ouflow component from the central source, 6 and 18 kpc, where we consider the 6 kpc location as somewhat more physically plausable. Assuming the canonical global covering of 20% for the outflow and a distance of 6 kpc, our analysis yields a mass flux of 120 M_sun yr^-1 and a kinetic luminosity that is ~0.1% of the bolometric luminosity of the object. Should the dust be part of the outflow, then these values are ~4x larger. The large mass flux and kinetic luminosity make this outflow a significant contributor to AGN feedback processes.Comment: Accepted for publication in ApJ, 57 pages, 14 figure

Star forming galaxies in the Hercules cluster: Halpha imaging of A2151

This paper presents the first results of an Halpha imaging survey of galaxies in the central regions of the A2151 cluster. A total of 50 sources were detected in Halpha. The morphologies of the 43 H$\alpha$ selected galaxies range from grand design spirals and interacting galaxies to blue compacts and tidal dwarfs or isolated extragalactic HII regions, spanning a range of magnitudes of -21 <= MB <= -12.5 mag. A comparison with the clusters Coma and A1367 and a sample of field galaxies has shown the presence of cluster galaxies with L(Halpha) lower than expected for their MB, a consecuence of the cluster environment. This fact results in differences in the L(Halpha) vs. EW(Halpha) and L(H\alpha) distributions of the clusters with respect to the field, and in cluster to cluster variations of these quantities, which we propose are driven by a global cluster property as the total mass. Overall, we conclude that both, the global cluster environment as well as the cluster merging history play a non negligible role in the integral star formation properties of clusters of galaxies.Comment: 38 pages, 11 figures. Accepted for publication in Astronomical Journa

Discarded livers tested by normothermic machine perfusion in the VITTAL trial:Secondary end points and 5-year outcomes

Normothermic machine perfusion (NMP) enables pretransplant assessment of high-risk donor livers. The VITTAL trial demonstrated that 71% of the currently discarded organs could be transplanted with 100% 90-day patient and graft survivals. Here, we report secondary end points and 5-year outcomes of this prospective, open-label, phase 2 adaptive single-arm study. The patient and graft survivals at 60 months were 82% and 72%, respectively. Four patients lost their graft due to nonanastomotic biliary strictures, one caused by hepatic artery thrombosis in a liver donated following brain death, and 3 in elderly livers donated after circulatory death (DCD), which all clinically manifested within 6 months after transplantation. There were no late graft losses for other reasons. All the 4 patients who died during the study follow-up had functioning grafts. Nonanastomotic biliary strictures developed in donated after circulatory death livers that failed to produce bile with pH &gt;7.65 and bicarbonate levels &gt;25 mmol/L. Histological assessment in these livers revealed high bile duct injury scores characterized by arterial medial necrosis. The quality of life at 6 months significantly improved in all but 4 patients suffering from nonanastomotic biliary strictures. This first report of long-term outcomes of high-risk livers assessed by normothermic machine perfusion demonstrated excellent 5-year survival without adverse effects in all organs functioning beyond 1 year (ClinicalTrials.gov number NCT02740608).</p

CfA4: Light Curves for 94 Type Ia Supernovae

We present multi-band optical photometry of 94 spectroscopically-confirmed Type Ia supernovae (SN Ia) in the redshift range 0.0055 to 0.073, obtained between 2006 and 2011. There are a total of 5522 light curve points. We show that our natural system SN photometry has a precision of roughly 0.03 mag or better in BVr'i', 0.06 mag in u', and 0.07 mag in U for points brighter than 17.5 mag and estimate that it has a systematic uncertainty of 0.014, 0.010, 0.012, 0.014, 0.046, and 0.073 mag in BVr'i'u'U, respectively. Comparisons of our standard system photometry with published SN Ia light curves and comparison stars reveal mean agreement across samples in the range of ~0.00-0.03 mag. We discuss the recent measurements of our telescope-plus-detector throughput by direct monochromatic illumination by Cramer et al (in prep.). This technique measures the whole optical path through the telescope, auxiliary optics, filters, and detector under the same conditions used to make SN measurements. Extremely well-characterized natural-system passbands (both in wavelength and over time) are crucial for the next generation of SN Ia photometry to reach the 0.01 mag accuracy level. The current sample of low-z SN Ia is now sufficiently large to remove most of the statistical sampling error from the dark energy error budget. But pursuing the dark-energy systematic errors by determining highly-accurate detector passbands, combining optical and near-infrared (NIR) photometry and spectra, using the nearby sample to illuminate the population properties of SN Ia, and measuring the local departures from the Hubble flow will benefit from larger, carefully measured nearby samples.Comment: 43 page

A Cell Cycle Role for the Epigenetic Factor CTCF-L/BORIS

CTCF is a ubiquitous epigenetic regulator that has been proposed as a master keeper of chromatin organisation. CTCF-like, or BORIS, is thought to antagonise CTCF and has been found in normal testis, ovary and a large variety of tumour cells. The cellular function of BORIS remains intriguing although it might be involved in developmental reprogramming of gene expression patterns. We here unravel the expression of CTCF and BORIS proteins throughout human epidermis. While CTCF is widely distributed within the nucleus, BORIS is confined to the nucleolus and other euchromatin domains. Nascent RNA experiments in primary keratinocytes revealed that endogenous BORIS is present in active transcription sites. Interestingly, BORIS also localises to interphase centrosomes suggesting a role in the cell cycle. Blocking the cell cycle at S phase or mitosis, or causing DNA damage, produced a striking accumulation of BORIS. Consistently, ectopic expression of wild type or GFP- BORIS provoked a higher rate of S phase cells as well as genomic instability by mitosis failure. Furthermore, downregulation of endogenous BORIS by specific shRNAs inhibited both RNA transcription and cell cycle progression. The results altogether suggest a role for BORIS in coordinating S phase events with mitosis